Field
Certain aspects of the present disclosure generally relate to wireless communications, and more particularly, to systems, apparatus and methods for adaptive persistent acknowledge priority control for bi-directional TCP throughput optimization.
Background
In wireless communication networks, e.g., time division synchronous code division multiple access (TD-SCDMA) networks, many applications may utilize concurrent bi-directional, e.g., uplink (UL) and downlink (DL), transmission control protocol (TCP) transmissions between a mobile user equipment (UE) and a base station (NB). In the presence of a UL TCP session, the TCP acknowledge packets (ACKs) that acknowledge reception of the DL TCP data are conventionally queued behind UL data in a buffer on the UE side. Because an ACK must be received before DL TCP data can continue transmission, queuing ACKs behind other UL data significantly reduces DL throughput. Such a reduction in DL throughput may be attributed to the large round trip time (RTT) caused by the delayed DL ACKs. Such a reduction in DL throughput can also be attributed to the fact that the DL TCP congestion window (CWND) cannot increase beyond the buffering limit of the network side, thus disallowing accommodation of large RTT by allowing many unacknowledged packets on the air. Accordingly, in order to achieve good DL and UL throughput simultaneously, appropriate UE buffer management policies are desirable.